Apparatus for grinding blades.



- F71 was,

I R. T. WINN. APPARATUS FOR GRINDING BLADES.

APPLIOATIOH FILED MAY 11, 1910. V 981,51 1 Patented Jan.10,19-11.

, jM/S R. T.-WINN.

APPARATUS FOR GRINDING BLADES.

APPLICATION FILED MAY 11, 1910.

Patented Jan. 10, 1911.

3 SHEETS-SHEET 2.

Lwertffn Idea/all R. T. WINN- APYABATUS FOE GRINDING BLADES.

APYLIGATIOK FILED MAY 11. 1910.

Patented Jan. 0,1911

3 SHEETS-SHEET 3.

N T D Smiths 'tjr rENT ori ice.)

RICHARD T. WINN, OF CLIFTONIlALE, MASSACHUSETTS, ASS IGNOR TO LESLIEMANU- FACTURING COMPANY, OF-BOSTON, MASSACHUSETTS, A CORPORATIONOFMAINE.

APPARATUS FOR GRINDING BLADES.

. the following description, in connection with the accompanyingdrawing, is a specification, like characters on the drawing representinglike parts.

, This invention has for its object the production-of improved apparatusfor grinding blades in a rapid. accurate and flicient -1nanner.

' My invention is particularly adapted for grinding safety-razor bladeswhi'ch blades are made of thin plate metal and require grinding onopposite sides to produce the requisite edge. p

In thepresent en'ibodiment of iny invention the blade to be ground isclamped in; a

self-centering blade-holder which is OSClllated or rocked between twooppositely r0--' 'tating and axially reciprocated grinders, to

thereby present one side. of the blade to he acted. upon by one.grinder. and then the holder 1s rocked to present the opposite side ofsaid blade to be acted upon by-the other grinder.

ly making the holder self-centering the blade positions itself upon thegrinder so as to contact therewith from one'to the other cnd of theblade, provided the surface of the grinder be true, but also permittingthe blade to adapt itself to the grinding surface for proper action'incase such surface should be slightly irregular. The axial movement ofthe grinders causes theni to act upon the blade from end to end, and avery perfect grind ng 1s achieved.

These and other novel features of my invcntion will be fully describedin the sub.-

- 'out in the followinp clan'ns.

joined specification and particularly pointed ing apparatus embodyingone form of my present invention, the movable parts being at rest, and Ihave omitted the driving belt for the main shaft and also thetransmitting belt between said shaft and the grinder shafts; Fig. 2 is atop plan view of the apparatus illustrated in Fig. 1, the-pipes forsupplying oil or water to the grinders being omitted. and also the beltfor'rotating the gruidcr shafts; Fig. 3 1S' 1l right-hand Specificationof Letters Patent.

Application filed May 11, 1910. Serial No. 50,585.

end elevation of the apparatus, viewing Figs. 1 and 2-, and showing tlretransniitting belt between the grinder shafts andthe main shaft; Fig.4.- is a left hand end elevation of the reciprocating h'eadby-means ofwhich the grinder shafts are reciprocated axially and in unison; Fig. 5is a transverse sectional detail on the line 55, Fi .-1,.1ooking towardthe' left,. showing t el bladeholder and its carrierand the relationthere- Patented Jan. 10, 1911.

of to the grinders; Fig. 6 is an enlarged detail in rear elevation "andpartfsection of the blade-holder and carrier; islai sectionalview'o'f'the blade-holderz-ontthe line 7 7 Fig. 6' Fig. 8- is:- a'perspective view of 5 blade zidapted 'toflbe' the apparatusembodyingzgfxny invention; Fig. 9 1s a view of one ofthe grinder shaftsound bv with its adjuncts shown'dnflongi'tudinaI seci tion, to.illustrate clearlyf-thconstructionpf i bereinafter. apparatus .are

various details to be referre The working parts of itli supported upona'suitabl i'li with depending hangers: 2 provide suitable bearings r a.main Shaft 4 provided at its oppo'site e iids with vWorms 5 (i andhaving loosely mounted upon it a pulley 7 adaptedtq be" driven by abelt, (not shown) from any' suitable'soilrce of power.

The inner end of thepfu lley is, recessed at 8 and forms one member9xpf'afg friction clutch,

the other'member beingl. as an annularlygrooved collar l0gconedat lltoenter and frictionally engage itheg recess .8.,vwhen the clutch isoperative, said collar infp'r'actice being rotatable witlr'andlfslidable on the main shaft fit, in welllknown manner. A shipper 12is fixed on a transverses'haft 13 mounted in ears depending from thebase,

4 i the shaft having fixedl secured to it a-yoke se. 1:..provided W F 1,which,

14 cooperating. withgt e clutch-member 10 to open or close the clutch,-the ship erhaving pivotallyconnected'witlrit 8. r0 .15'slidable in anear 16 .on the .base, Taspring'l? coiled around said rod'between the earand a collar 18 fast on therodaacting, when free to expa nd,toswing theshipper'to'open the clutch. J E

In Figs. 1 and 2the ship er'is shown in stopping position, and in or erthat the main shaft may be stopped pron'i tly when the clutch is openedI have pi'ovi I ed theiyoke 14: with a depending brake arm 19' "having.a friction pad or shoe 20 which-isgfpressed against the side of agrooved diskpplley '21 fast on the shaft. When the shipper 12 is havingan attached pinion 26, both rotatable two'large and like meshing gears30, 31, Fi

on a horizontal stud 27 carried by the base 1 at the right-hand endthereof, Figs. 1 and 2. Transverse, upright stands 28, 29 are erected onthe base, the former about the middle and the latter at the right-handend thereof and 3, are rotatably mounted -on suitable stu s extendedoutward from the stand 29, the

.gear. 31 meshing with and being driven by the pinion 26. Like earns 32,33 are secured to or form a part of the said gears 30,- 31.at theirinner sides, each cam as shown by dotted lines Fig. 3 having a longcircular high part which in, practice constitutes "a dwe1l, with a quickrise to and fall from such part. v

As Shown in Fig. 3 the two cams are set so that the high part/of onewill not begin to act until the high art of the other cam ceases to act,as will clearly hereinaftenthe arrows indicatin the direction ofrotation of the cams an their connected gears. Herein I have -pro= vidcdtwo rotatable, longitudinally movable and parallel shafts 34, 34, oneach of which a grinder 35 is fixedly mounted, and inasmuch as theshafts and grinders are alike a detailed description of one will sufiicefor both. .Said shafts are supported horizontally in bearings shown asboxes 36 set into recesses inthe stands 28, 29 and held in place bycover-plates 37*, each box having a cylindrical bore in which is fixed aguard sleeve 37 in which the shaft rotates and is movablelongitudinally, each of said sleeves extending along the shaft towardthe grinder I 35, see 9, said grinders being of'any 5O suitableconstruction and material and cylindrical, and of greater length-thanthe blades to be ground. A disk 38 fast on each shaft serves as an endstop for the grinder, and at its opposite end a clamping nut 39 is setup tightly on'a threaded part 40 of the shaft, to secure the grinderfixedly upon its shaft. Oppositely extended sleeves 141, 42 are securedto the stop 38 and nut 39 respectively, and they telescopically embracethe fixed guard sleeves 37, so that as the shaft 34. is reciprocatedlongitudinally the two pairs of telescoping guard sleeves willeffectually prevent the entrance of grit or dirt to the shaft bearings.Practically, the

-' sleeves 37 form parts of the bearing boxes be explained moreandsustain the shafts, as will be clear from Fig. 9.

In Fig. 9 the shaft is at the extreme left hand end of its stroke, theguard sleeve 41 closely approaching the box 36 at the left, and theouter end of the guard sleeve 42 fixed sleeve 37at the right. During thegrinding operationv particles of grit, steel not for the provision madefor protecting the bearings of the shafts .th'ey would be rapidly cutand worn out. 'The boxes 36 mounted in the stand 28 are provided withcylindrical extensions 43, annularly shouldered at 44, Fig. 9, andthreaded at 45, and upon each extension is mounted rotatably a groovedpulley 46, held thereon by a nut leys 46 are opposite each other andabove the large pulley 21 on the main shaft 4, and an endlesstransmitting belt 48 passes around pulley 21' up over a tension pulley49 adjustably mounted-on anarnr 50 erected on the base 1, said belt"passing thence to and under the rear one of the smaller pulleys 46 andu around and over the front pulley 46 an b ack. to the driving pulley21, as shown in .-Fig. 3. By this connection the pulleys 46 are rotatedat high speed from as shown by the arrows 51, Fig. 3, the adjacentsurfaces, of the grinders traveling up ward and outward, away from eachother.

The transmitting connection heretofore described between the main shaft4 and the cams 32, 33 is positive and reduhes'thc. speed of the camswith relation to the main shaft, while the friction transmission betweensaid shaft ,and the .grinder shafts increases the speed of rotation ofthe latter very greatly over that ofthe main shaft, as will be ob vious.Each pulley 46 has fixedly attached to it a plurality of axiallyextended rods 52 which slide in holes in 'a disk 53 fast on the grindershaft" 34 near its left-hand end.

ting longitudinal or axial reciprocation thereof in its fixed bearings.A second disk ranged to rotate freely in a slot $5 in a reciprocatinghead 56, F1gs.,1, 2 and 4. having an attached sleeve 57 slidably mountedward from the standard 28, and below and 60 on said head, Fig. 4. Saidhead thus connects the two grinder "shafts'and eflects axialreciprocation thereof in unison by mechanism connecting the head and theanain-shaft 4, new to be described. Y

overlaps by a safe margin the end of the and dirt are given off freely,and were it the main shaft 4, and in opposite directions,

54-fast on the end of each shaft 34 is ar-- 47 screwed onto the part 45.The two pul-' to effect rotation of the shaft while permit on' ahorizontal guide-rod 58 extended outparallel to said rod is a.secondguide-rod 59 which is loosely embraced by a slotted. ear' A link 61 ispivotally connected at one end to an car 62 on the head-56j, .and at itsother end pivotallyengages a crank '63 on 1 the tail of a pawl-carrier70fu 981,611 I i I t {the upper end ofa vertical counter-shaft 64-rotatable in a sleeve bearing 65 on the base,

and in a second bearing66 on bracket 3,'a

wormgear 6'7 on the lower end of said shaft meshing with"and'beingdriven at a slow speed by the worm G on the main shaft Fig. 1. As shaft64 is slowly revolved the link 61 acts to reciprocate the head 56 andthe grinder shafts, sothat the two rotating grinders 35 are reciprocatedaxially at a slow speed, said grinders being shown at the extreme lefthand end of their stroke in Figs. 1 and 2. At the to of the bearin (35 acam 68 is fixed on sha t 64 by means 0? a long hub 69, said capicooperating with crumed on an upright post 71 on .the base'and heldagainst the cam by a spring 72, only partly shown in Fig. '1 to avoidconfusion. An ordinary spring-pawl 73 on the pawl-carrier cooper- 1 ateswith a ratchet 74 rotatable on said post above the pawl-carrier, andheld from retrog aderotation by a detent-pawl 75,

. Clearly shown in Fig. 2.

A vertical spindle 76, Fig. l, is sustained in suitable bearings\77,'and carriesat. its

upper end a trip finger 78projectingacr0ss the top of the ratchet in thepath of 2'. lu 79' thereon," and-'near its lower end sai spindle hasfixed upon-it a latch 80, adapted to engage inholding notch 81, Fig. 2,in the rod 15 connected with the. shipper 12. The latch is pressedagainst the said rod by a spring 82 coiled around spindle 76 and fixed.at its upper end to thebearing 77, the free lower end of the springbearing against the latch. Every revolution of cam 68 causes the pawl 73to turn the ratchet-74 one step forward, and one complete revolution ofthe ratchet will cause the lug 79 to engage the trip finger 78 and turnthe spindle 7G to withdraw thelatch from the holding notch 81, therebyreleasing the shipper 12' and permitting the spring 17 to operate andmove the 'shipper'to stopping position, shown in the drawings. Thus theapparatus is stopped automatically after a redetermined number of:reciproc'ations' of tlie grinders 35 has been effected, such numberbeing i suflicient to provide a proper grinding of,

a blade. This form of automatic stop-mo- 'tion is simple, convenient andefiicient, but any other suitable form of stop-motion may beutilizedwithout departing from my invention." V 3 The means forholding-the blade'to be ground, and for presenting opposite sidesthereof to the grinders, in alternation, will now be described. Thestandards 2-8, 29 are herein shown as provided with opposite bearings83, for a shaft 84 forming part of a rocking. carrier, said shaft beingheld from longitudinal movement bysuitable colhrs 85 and projecting atitsg'ends beyond the standards, the inner'end having attached to:

turned manually to neutralposition. Said shaft '84 has fixedly securedto it betweei'i the collars 85 a block 87 provided -'with fan upturnedrectangular part 88 provided with it a handle 86 by which the carriermay a hole'or seat 89,Figs. 5 andG, malta to 'et 91in the, side bruteattached block constitute whatI hayeite r'med wrecking or oscillatingcarricufor a o able blade-holder, the carrier bein f t below and betweenthe grinder shafts rgd herein shown, the shaft '84 being p'a a' thereto..The projecting end oftlie ea 1' shaft 84 beyond the standard 29. has

upon it a transverse yoke92, Fig. 3, ha,vi ng cars 93 at op osite sidesofthe shaft on which ears ar'e-plvoted short arms .94 ,pro

vided at their outer endYwith fo llfower rells 95 which cooperatewithth'etwo ca'ins32 hereinbeforc described, coiled" springs 95 ad.- justably held by' screw-studs 971m the yoke \acting upon the arms andyieldingly -press ing the rollsg95.against the cams.

- From; an inspection of Fig. ,3

manifest that when a high part- .of ,-eitl1er cam acts upon one of therolls 9Q thaend-ofthe yoke 92 will-be raised and the rc arrier will berocked in the opposite.direetioniythe ir springs -96 being strongenougli tof provide for the rocking ofthecarricfbut yielding whenresistance to the rocking movement; s

. encountered. As shown in Fig. 3 the cent 33 is ac'tingto rock thecarrier, sothat;= the blade mounted thereon will be swung to. the leftand presented' to the action'of the left. hand grinder '35, while thecam 32 will=not effect the reverse swing of the carrier until the highpart of cam 33 leaves the cooperate ing roll 95. Thusthe carrierisl'rocked or oscillated 1nterm tt1ngly, :.-thejlongh1gh or dwellortumof eacl1 cam insuring a period of rest after each saving. of thecarrier, and

herein this rest period is .longgenou'gh for the grinders to makeonecoinplete RXlfll-TG- ciprocation. That is, referring to FigJQthegrilidel's'ovill more to the .rightrandthefi back againtothe positionshown beforedhe cam 33 will permit the quick reverse hiding of thecarrier as the cam-32 acts fo'move' its follower-roll 95' along thequick ris'ejto 'the' long circular portion of its surfaee. gMy present apparatusis arranged to g'rind blades used in safety-razors, such"abladebes fore it 1s ground belng shown in perspect ve at 98,-Fig. 8, and inpractice thesebla'des are cut or stamped out of thin, sheet, steel. andsuitably hardened. To be ground the blad'e' is'placed in a blade-holderherein shown as;-

comprising a fiat, reetangularb'asc 'QQFhaV-i ing a centrally locatedand -depe'rnding"st'n'i, 100 annularly grooved at'lOl, theb'a'se'ha'y-f'; ing an upright portion 102; forming beingconnectedtherewith by a clamping spring into the annular groove 101 in thecutting edge of the blade, both sides of which .105, adjacent theblade-engaging portion, the

between the tapered ends 105' of the clamp pressed yieldingly thereonowing to the coinlVhile the apparatus is in .opera tion the member of aclamp, the other member 103 bolt 104.

As shown in Figs. 5 and '1 the upper ends of the clamping members areconcaved, at

fixed member 102 having its inner face cut out to form a blade-seat 106extended from end to end of the said member. The clampscrew 104: isloosened, a blade is slipped in members and seated on the blade-seat106,and the screw 104 is then set up, the blade being thereby firmly andsecurely clamped, and positioned in the blade-h0lder, w1th the ortionsof the blade to be ground pro ectlng well beyond the holder. N ow thelatter is connected with the carrier by inserting the stem 100 in theradial seat 89, the tapered end of the stem passing by and pushing outthe plunger 90 until it is free to snap or stem, as shown inFigt. Aquick-acting detachable coupling or connection between the blade-holderand the rocking carrier is' thus provided, the'holder being retained onthe carrier to move bodily with it, but at the same time the holder isfree to turri on the stem 100 as'an axis. I thusmake the bladeholderself-centering so that it can adjust itself to the grinding surface whenthe blade is presented'thereto by the rocking of the carrier, previouslydescribed.

The holder, when mounted on the carrier, is located between thegrinders, and the blade is applied tangentially to the surface of eithergrinder, as will be manifest from an inspection of Fig. 5, along a linejust above the horizontal planc'intersecting the axes of rotation of thegrinders. The throw of the carrier-rocking cams is such that when the"blade is brought against a grinder it will be pression ofthe then activeone of the springs 96, and owing to the self-centering feature of theblade-holder the blade adapts itself automatically to the grindingsurface as the rotating grinder is moved longitudinally along the blade.I I

blade Will be presented automatically to one and then to the other ofthe grinders to effect the grinding of the opposite sides of the bladein alternation, the curvature of the grinders giving the desiredcrmcavity to the will be ground alike. A positive limitation of theoscillatory inm'cment of the carrier and blade-holder is provided by thestopscrews 107 carried by cars 108 on the standard 29 and arranged tocooperate with the yoke 92 at opposite sides of the shaft 84 of thecarrier. Each screw when adjusted determinesjust how far the blade inthe holder be. moved toward the axis of a grinder,

and if it is desired to grind one side of the blade more than the otherside, or if one of the grinders has worn more rapidly than the other,the proper adjustment of the stopscre'ws provides for either case.

In practice a number of blade-holders will be used with each grindingapparatus, so

that the attendant can take out the holder with the ground blade,insert'anoth'er holder having a blade to be ground, and start themachine, and during the, grinding operation he will remove the groundblade and put an unground one in the holder.

Any suitable means can be provided for supplying the grinders with oil,water, or-

other liquid during the grinding operation,

and in Figs. 1 and 5 I have shown the deliv-- claims annexed hereto.

Having fully described my invention, what I claim as new and desire tosecure by Letters Patent is 1. The combination, withtwo oppositelyrotating and longitudinally-movable parallel shafts, a grinder fast oneach,"and means to rec 'ocate the shafts positively and in unison, of arocking carrier, a self-centering blade-holder between the grinders andmounted on said carrier, and means tointermittingly rock the iatter andthereby present a blade in said holder to one and then to the other ofthe rinders, to grind opposite sides of the blade inalternation.

2. The combination, with two oppositely rotating andlongitudinallysmovable parallel shafts, a grinder-fast on each, andmeans ,to reciprocate the shafts positively and in unison, of arocking-carrier, a blade-holder, a detachable and self-centeringconnection between it and the carrier', and means to intermittingly rockthe carrier and thereby present a blade in the holder to one and .thento the other of the grinders and grind opposite sides of the blade inalternation.

3. The combination, with two oppositely rotating andlongitudinally-movable parallel shafts, a grinder fast 'on each, andmeans to' 4 rotating and longitudinally-1novable parallel shafts, agrinder fast on each, and meansto cams and cooperating,spring-controlled fol son, of a rockingcarrier fulcrumed-below a bladein the holder against first one and the carrier, spring-controlledfollowers, on?

the other ofsaid grinders and ress-it yield- '35- ingly against thegrinding snr ace.

ground and means to reciprocate the shafts .shafts. a cylindrical,grinder fast on. each between the grinders, and intermittingly actingmeans to rock the blade-holder and present a blade therein to one ofsaid grinders during a complete axial reciprocation thereofand then tosimilarly present the blade to the other grinder.

5; The combination, with two oppositely reciprocate the shaftspositively and in uni, son, of a self-centering blade-holder locatedbetween the grinders, and intermitting'ly acting means, includingoppositely rotatnlg lowers, to rock said blade-holderand yieldinglypress a blade therein against one 'and then the other of the. grinders,to grind opposite sides of .the blade in alternation;

6. The combination, with two oppositely rotating and longitudinallymovable parallel shafts, a grinder'fast on cash, and means toreciprocate the shafts positively andin uniand parallel to said shafts,a yoke fast'on said yoke at opposite sides of the carrier axis, and twooppositely rotating cams having high portions to cooperate in successionwith the followers, to intermittin ly rock the carrier, a blade-holdermounte on the carrier and adapted to oscillate between the grinders, topresent a blade toone and then 7. The combination, with two oppositelyrotating and longitudinally-movable parallel shafts, a cylindricalgrinder fast on each and of greater length than the blade to bepositivel and in unison, of a self-centering blade-ho der locatedbetween the grinders, and automatic means to rock the blade holder andyieldinglypress a blade therein against one and then the other of thegrinders, the blade being subjected to the action of a grinder during acomplete axial reciprocation. thereof.

8. The combination, with two oppositely rotating and longit udinallymovable parallel and of greater length than the blade to be ground, andmeans to-reciprocate the shafts positively-and in unison, of a rockingcarrier, a holder to clamp a blade therein, a detachable, self-centeringconnection between said holder and carrier, ,to sustain the holderbetween the grinders, oppositely rotating cams, and yielding connectionsbetween said camsand the carrier, to rock the latter and the holderinterin-ittii'igly and yieldingly press thenthe other of the grinders asthe latter are reciprocated axially.

' 9. The combination, with two oppositelv rotating andlongitndinallyanovahle paralvtion between the blade-holder an andintermittingly actin means to'r'ock thelel shafts, a grinder fast oneach, and means to reciprocate the shafts positively and in unison, of arocking carrier having a radial seat, a blade-holder having astem toenter unison, of a rocking carrier having a radial seat, a blade-holderhaving an annularly grooved stem to enter the seat, a springplunger onthe carrier to enter-said groove .and retain the stem in-the seat whileper mitting rotative movementofthe stem therein, andmeans to rock said,carrier interinittingly and therebypresent a blade in. the.

holder to one and then the other ofv the grinders, the connectionbetween -the. car:

rier and blade holderpennitting the latter to center itself withrelation to a grinderw 11. The combination, with two-opositelyrotatingand longitudinall'y-movab e parallel shafts, a grinderfast on each, and means to reciprocate .the'shafts positively and inunison, of a rocking carrier, a blade-holder having a seat for the bladeand aretaining I00 connecclamp, a detachable, self-centerin carrier,

carrier and oscillate theb ade-holder between the grinders, to present ablade in said,

holder to the action of first one and then the other of the grinders. ri

12. The combination,' with two 0 positely rotatim andlongitndinally-movab e parallel shafts, a grinderfaston each, and meansto reciprocate'the shaftj'positively and in unison, of a rocking car'icr,aself-centering blade-holder betweenthe grinders and 'mounted onsaid-carrier, yieldingly mounted followers. on the carrier at oppositesides of 115 its axis, two oppositely rotating cams to co' operatesuccessively with'ithefollowers and thereby rock the carrier andblade-holder, to

press a blade in said holder yieldingly I i against one grinder and thenagainst. the;

other grinder, whereby opposite sides' of the blade are ground inalternation.

l3. In appar grinder shaft, fixed-bearings 'in-which 1t .15 movablerotatably and longitudinally, a grinder fast on the shaft between saidbear atus. of the class .described,.a I

ings, andtelescoping guards mounted-{0x1 said' bearings-and the, shaft,-;rcspee tively r and surrounding the latter to protect =the hearingsfrom grit 1 14. In apparatus of the class described, a

fixed uard sleeve surrounding the shaft and bearing, a

extended inward from each grinder fast on the shaft between the bearmgs,and guard Sleeves fixed on'and surrounding the shaft and extendedoppositely from the grinder in telescopic engagement with the fixedsleeves, to prevent the entrance of grit to the bearings.

15. In ap aratus of the class (.lescribcd, a

' grinder sha t, fixed bearings in which it is movable rotatably andlongitudinally, a "Illldl" fast on the shaft between sald bearings andtubular, telescopic guards surroundving the shaft between the grinderand said hearings, to permit longitudinal movement of the shaft whileprotecting it and the grinder shaft, fixed bearings in which it isbearings from the entrance of dirtor grit.

16. In apparatus of the class described, a

movable rotatably and longitudinally, and tubular, telescopic guardssurrounding the shaft between the grinder and said hearings, to permitlongitudinal movement of the shaft while protecting it and the bearingsfrom the entranceof dirt or grit, combined with a driving. pulleyloosely surrounding said shaft outside one of the bearings, axiallyextended pins 'fixed on the pulley, a disk fast on the shaft andapertured to slidably engage said pins, whereby rotative movement of thepulley is transmitted to ,the shaft, and means to effect longitudinalmovement of the shaft with respect to the bearings and said drivingpull'ey.

17. In apparatus of the class described, two oppositely rotatable andlongitudinally reciprocating, parallel shafts, a grinder fast on each,ablade-holder between the grinders, intermittingly acting means to rocksaid holder to present a blade therein to one and then the other of thegrinders, a main shaft, a. high-speed transmitting connection between itand the grinder shafts, to rotate them, and a separate. low-speedtransmitting connection between the said main shaft and the means forrocking the bladeholder.

'- 18. In apparatus of the class described,

movable, parallel shafts, a grinder fast on each. an oscillating,self-centering bladeholder between the grinders, means to rock saidholder intermlttingly and thereby present a blade therein to one andthen the other of the grinders, a main shaft, independent transmittingconnections between it and the grinder shafts and the blade-holderrocking means, and means actuated by the main shaft and oper'ativelyconnectcdwith the grinder shafts to effect longitudinal reciprocationthereof in unison.

l9. In apparatus of the class described, two oppositely rotatable andlongitudinally reciprocating, parallel shafts, a grinder fast on each, ablade-holder between the grinders, intermittingly acting means to rocksaid holder to present a blade therein to one and then the other of thegrinders, a main shaft,

grind-er shafts, to rotate them at high speed, a speed-reducing train ofgearing between i the main shaft and the means for rocking theblade-holder to actuate said means, a driving pulley loose on the mainshaft, a clutch to operatively connect saidshaft and pulley, and a brakefor the main shaft, rendered operative by'release of the clutch.

20. In apparatus of the class described, two oppositely rotatable andlongitudinally reciprocating, parallel shafts, agrinder fast on each, ablade-holder betweenthe "rinders, intermittingly acting means to roclrsaid holder to present a blade therein to one and then the other of thegrinders, a main shaft, a high-speed transmit-ting connect-ion betweenitand the grinder shafts, to effect rotation thereof, and a separatetransmitting connection between the means for rocking the blade-holderand the main shaft, combined with means actuated by the main shaft toeffect axial reciprocation of the grinder shafts in unison, andmechanism to stop rotation of the main shaft automatically when apredetermined number of reciprocations of the grinder shafts has beenefiected.

21. In apparatus of the class described, two oppositely rotatableandlongitudinally reciprocating, arallel, shafts, a grinder fast oneach, a bla e-holder between the rinders, intermittingly acting means toroc said holder to present a blade therein to one and then the other ofthe grinders, a main shaft, separate transmitting connections betweenthe main shaft and said grinder shafts and the means for rocking theblade-holder, means driven by the main shaft to reciprocate the grindershafts axially in unison, and 'mechanism to stop rotation of the mainshaft automatically when a predetermined number of reciprocations of thegrinder shafts has been effected.

22. In apparatus of the class described, two oppositely rotatable andlongitudinally reciprocating, parallel shafts, a grinder fast on each, ablade-holder between the 'nders, intermittingly acting means to roc saidholder to presenta blade therein to one and then the other of thegrinders, a main shaft, separate transmitting connections between themain shaft and said grinder shafts and the means for rocking theblade-holder, means driven by the main shaft to reciprocate the grindershafts axially in unison, a shipper to throw the power on and off saidmain shaft, a spring to move the shipper to stopping position,alat'ch'to hold the ship per in running position, and means to re= tractsaid latch and thereby release the shipper when a predetermined numberof a belt transmission between it and the I .i'eciproei tions of thegrinder shafts has been effected.

ingly presse blade therein against one and then the other of thegrinders, to grind opposite sides of the blade in alternation, and adgustsble stops to limit the rocking movement oi the blade-holder ineither d1- reetion,

24:, The combination, with two oppositely rotating andlongitudinallyqnovsble parallel shafts, 2i grinder fast on each, andmeans to reciprocate the shafts positively and in unison, of a rockingcarrier s. self-centering blade-holder between the grinders and mountedonseid carrier, opposite radially extended followers yieldingly mountedon the carrier means, including rotating cams cooperating with-thefollowers; to roelethe carrier and blade-holder end yieldingly pressahisde therein against first one and then the other of said grinders,independent,adjustable stops to positively limit rocking movement of thehlailehohler.

The combination, with two oppositely rotating and longitudinally-movableparal lel shafts, at grinder fast on each, and means to reciprocate theshafts positively and in unison, of a rocking; carrier, atself-centering bladehohler between the grinders and mounted on saidcarrier; automatic means to roel: the carrier and present a blade in theholder to one and then to the other of the grinders, and s handleconnected with the carrier to position the blade-holder midi: 3' betweenthe grinders.

26. In apparatus of the class described, two oppositely rotating andlongitudinallymovable parallel shafts, a grinds: fast on each, fixedguides between and parallel to said shafts, a transverse, slotted headslid- :ihly mounted on said guides, disks fast on the shafts and looselyentering the slotted.

portions of said head, and means to recipro cste' said lieiirl on theguides whereby through cooperation with sand disks-the head effectslongitudinal reciprocation of the"- giinder shafts in unison.

In testimony whereof, I have signed my some to this specification,iii-the presence of two subscribing Witnesses.

liilQ l'ljillll 'll. ll lli N.

'llitnesses Joni: C, Examines, FREHEERICKL .S. ii'REENLEAE.

